PowerPoint-Pr

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Performance evaluation technology of
photovoltaics for certification calibration
Kengo Morita TÜV Rheinland Japan Ltd.Solar
Energy Assessment Center (SEAC) 4-5-24
Chigasaki-higashi, Tsuzuki-ku, Yokohama 224-0033,
Japan Tel [phone] Direct
81-45-914-0439 Fax [phone] email
kengo.morita_at_jpn.tuv.comhttp//www.tuv.com
No part of this presentation may be reproduced in
any form or by any means without the permission
fromTÜV Rheinland Japan - Photovoltaic
Department.
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Outline

• About us
• Importance of performance evaluation
• General concept for performance evaluation of
  PV modules
• Our facilities for the performance measurement
• Measurement technique of
• - Single amorphous
• - Multi junction (ex a-Si / µc-Si)
• - CIS
• Future Plan

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About Us

• Established as a pressure vessel inspection
  organization we have been offering international
  safety and system management certification for
  over 130 years.

People
Environment
Technology
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Industries served by the TÜV Rheinland Group
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Our activity in PV field
- PV module certification program IEC 61215
and IEC 61730 Crystalline IEC 61646 and
IEC 61730 Thin Film Factory inspection -
Calibration Measurement Services of
Photovoltaics - Type approval of PV module
components Accreditations Our testing laboratory
conforms to ISO/IEC 170252005 - IECEE CB
Accreditation - JNLA ASNITE Accreditation by
IA Japan - DATech Accreditation by DAR (Germany)
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SEAC (Solar Energy Assessment Center)
Opened in Yokohama city on 2009/6/15
The SEAC provides evaluations of the Thin Film
Modules and Calibration Services.
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Importance of performance evaluation
Simplified test sequence of certification program
(IEC61215, 61646)
Visual inspection, power determination,
insulation test (dry and wet)
UV preconditioning
Hail impact
Mech. load test
Light-soaking ? only IEC 61646
Visual inspection, power determination,
insulation test (dry and wet)
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Importance of performance evaluation

• Certification testing
• Simplified pass criteria regarding performance
• - For crystalline Si (IEC61215)
• Degradation rate of each test lt 5
• Degradation rate of each sequence lt 8
• - For thin-film (IEC61646)
• Pmax at STC after light soaking gt 90 of
  Pmax of min_value
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  specified by manufacturer
• Calibraton testing
• Measured module is used as reference module for
• measurement control of production line

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General concept for performance evaluation 1.
Relevant standards

• IEC60904-1 (IV measurement method)
• IEC60904-2 (Reference cell module
• with calibration method)
• IEC60904-3 (Measurement principles
• with reference spectral
  irradiance data)
• IEC60904-4 (Traceability)
• IEC60904-7 (Computation of the spectral
  mismatch
• correction)
• IEC60904-8 (spectral response measurement
  method)
• IEC60904-9 (Requirement of solar simulator)

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General concept for performance evaluation 2.
Standard test condition (STC)

• Irradiance 1kW/m2
• Spectral irradiance
• distribution AM1.5 G,
• Reference spectrum
• Temperature 25?

Reference spectral irradiance (AM1.5G)
Reference spectral irradiance is determined by
IEC60904-3. The performance of photovoltaics
should be measured based on standard test
condition.
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General concept for performance evaluation 3.
Reference solar cells
Spectral response of some kind of general
photovoltaics
Photograph of reference solar cell
The spectral response of reference solar cell
should be similar to tested sample. Otherwise
spectral mismatch error is induced.
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General concept for performance evaluation 4.
Spectral mismatch evaluation
What is spectral mismatch error ?
FS (?) Reference spectral irradiance Fm (?)
Spectral irradiance of used solar
simulator Q1(?) Spectral response of reference
solar cell Q2(?) Spectral response of tested
sample
(IEC60904-7 Computation of the spectral mismatch
correction for muasurement of photovoltaic
devices)
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Our facilities for performance evaluation 1.
Photo of solar simulator
Long pulse solar simulator (LPSS)
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Our facilities for performance evaluation 2.
Specification of LPSS
Available test area 2.01.4m Class AAA in
accordance with IEC60904-9 Ed.2 - Spectral
irradiance Air Mass 1.5G, Variable type
lt25 according to
IEC60904-9 - Non-Uniformity lt2.0 (Class A) -
Stability of Pulse within 2.0 Maximum pulse
duration 800msec Lamp 6 Xenon short-arc lamp
(5kW) Accuracy of current voltage
measurement lt0.2
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Our facilities for performance evaluation 3.
Measurement data of Non-Uniformity ()
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Our facilities for performance evaluation 4.
Measurement data of Spectral match
Match to crystalline Si (IEC/JIS)
Match to amorphous Si (JIS)
Spectral irradiance of solar simulator
Check every month
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Our facilities for performance evaluation 5.
Measurement data of Temporal instability
Sample Isc after irradiance correction (Sample
Isc / measured irradiance by reference range)
Irradiance during 1 pulse (Measured Isc /
calibrated Isc)
LTI 0.9
Accuracy of irradiance correction 0.1 (This
is the concept of STI)
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Our facilities for performance evaluation 6.
Measurement procedure
1. Check of spectral response of the tested
sample to be measured 2. Spectral mismatch
evaluation (IEC60904-7) 3. Set of the tested
sample and reference cell (Reference cell
should be set at the position of average
irradiance in the area of tested sample.) 4.
Temperature control (tested sample and reference
cell) 5. Check of sweep direciton and sampling
speed 6. Adjustment of irradiance 7. Measurement
of current and voltage of the tested sample
irradiance (current of reference cell) at same
time during sweeping voltage, 250point,
repeat time 3) 8. Data analysis
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Our facilities for performance evaluation 7.
Uncertainty
Isc 2.0 Voc1.1 Pmax2.3 (coverage factor
k 2)
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Our facilities for performance evaluation 8.
Measurement Reproducibility of Pmax, Isc by
our measurement system during 6 months
Isc 0.2 (2s)
Pmax 0.6 (2s)
Sample mono-crystalline Si, 1.61.0m
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Example of Test Report of IV measurement
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Measurement technique for thin-film type
Results from the Second InternationalModule
Inter-comparison
S. Rummel et al., 2006 IEEE 4th World Conference
on Photovoltaic Energy Conversion (WCPEC-4) held
May 7-12, 2006 in Waikoloa, Hawaii
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Measurement technique for thin-film type
1. single amorphous
Reference solar cell Pseudo amorphous reference
cell
Additional filter type
Identification type
encapsulated type
Structure Crystalline Si with optical filter
which spectral response is similar to tested
amorphous cell)
Spectral mismatch evaluation
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Measurement technique for thin-film type
1. single amorphous
Solar simulator
lens
Reflection light
Incident light
Re-reflection
Ref Cell
Light angle characteristics of reference cells
Irradiance measurement error is induced by
multi-reflection. One of solution is structure of
reference cell.
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Measurement technique for thin-film type 2.
Multi-junction
Double junction consists of top cell (exa-Si)
and bottom cell (exthin film c-Si) with
difference range of spectral response Series
connected structure (TopBottom)
Spectral response of top cell and bottom cell of
multi (double) junction cell
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Measurement technique for thin-film type 2.
Multi-junction
Tandem modules are series connected structure
The current of the module is limited to the
current of the cell with the lower Isc (Top or
Bottom)
IV characteristic of the module strongly depends
on the spectral irradiance distribution of the
light source.
It is more difficult to evaluate STC performance
than that of single junction cell
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Measurement technique for thin-film type 2.
Multi-junction
Spectral dependence characteristics of
multi-junction cell
IV characteristic of the multi-junction cell
strongly depends on the spectral irradiance
distribution of the light source.
Source Fraunhofer ISE
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Measurement technique for thin-film type 2.
Multi-junction
Measurement procedure for double-junction
1. Measure spectral response of top and bottom
cell (tested sample) 2. Make 2 reference
component cells used by stable crystalline Si
cell with proper optical filter based on spectral
response data of tested sample. 3. Measure
spectral response of 2 reference component cells
4. Confirm that these reference cells are
relatively equivalent to that of tested sample
(Spectral mismatch evaluations) 5. Calibrate each
reference cell in accordance with IEC60904-2 6.
Measure IV characteristic of tested sample at the
condition that irradiance level measured with
each reference component cell is 1 Sun (kw/m2)
(This condition is equivalent to AM1.5G for
double-junction)
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Measurement technique for thin-film type 3. CIS
Spectral response of CIS and crystalline-Si
Reference solar cell Crystalline-SiNeed
spectral mismatch correction
http//www.showashell-solar.co.jp/index.html
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Measurement technique for thin-film type 3. CIS
Light soaking effect, annealing effect of CIS
solar cell
Preconditioning should be determined before
performance measurement
http//www.tech.nedo.go.jp/
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Future plan

• Calibration of secondary reference cell
  module- Research for Performance evaluation
  method Proper structure of reference device
  for amorphous multi-junction Spectral
  adjustment technique for multi-junction
  Proper preconditioning for CIS New method
  for new technology (DSC, Organic cell)
  Traceability to production line - Research
  for Reliability evaluation method Long-term
  outdoor exposure test Correlation between
  Lab test and outdoor test Acceleration test

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